The subject invention relates generally to gas turbines. More particularly, the subject invention relates to fuel nozzles for gas turbine engines.
Gas turbines typically include a quantity of fuel nozzles (or swozzles) in a combustor section of the gas turbine. Each nozzle is a component having one or more passages for delivering a mixture of fuel and air to a combustion chamber for ignition. A fuel nozzle often includes a swirler to improve mixing of the fuel and air into a consistent, homogeneous mixture prior to ignition. The swirler includes a plurality of vanes extending from the nozzle and having an aerodynamic profile. The swirler vanes often include passages which provide fuel to fuel holes on a surface of the swirler vanes. As fuel exits the fuel holes, it mixes with fluid, typically air, passing the swirler vanes. Size and space limitations usually result in swirler vanes having an abrupt turn near the trailing edge of the swirler vane that may produce flow separations in the swirler or downstream of the swirler which can lead to detrimental effects on fuel nozzle performance, for example, flame holding. Typically, to solve flow problems such as the above, the vane profile is modified requiring new casting processes and casting tooling for each iteration, modifying the pattern of fuel holes on the vanes which may have detrimental effects on, for example, mixing efficiency and thus nozzle performance.